JP6977047B2 - Control method of extreme ultraviolet light generator and extreme ultraviolet light generator - Google Patents

Description

The present disclosure relates to an extreme ultraviolet light generator and a control method for the extreme ultraviolet light generator.

In recent years, with the miniaturization of semiconductor processes, the miniaturization of transfer patterns in optical lithography of semiconductor processes has rapidly progressed. In the next generation, microfabrication of 70 nm to 45 nm and further microfabrication of 32 nm or less will be required. Therefore, for example, in order to meet the demand for fine processing of 32 nm or less, exposure in which an extreme ultraviolet light generator that generates extreme ultraviolet (EUV) light having a wavelength of about 13 nm and reduced projection reflection optics are combined. The development of equipment is expected.

The EUV light generator includes an LPP (Laser Produced Plasma) type device that uses plasma generated by irradiating the target material with pulsed laser light, and a DPP (Discharge Produced Plasma) device that uses plasma generated by discharge. ) Type device and SR (Synchrotron Radiation) type device using synchrotron radiation have been proposed.

U.S. Patent Application Publication No. 2009/0057567 International Publication No. 2017/084872

Overview

An extreme ultraviolet light generator according to one aspect of the present disclosure has a chamber and a reflective surface located inside the chamber that defines a first focus and a second focus, a first focus and a second focus. An EUV condensing mirror configured to position the reflective surface and the second focal point across the first surface perpendicular to the first straight line passing through the first focal point and passing through the first focal point, and the first At least one magnet that generates a magnetic field around the focal point and the first focal point, and is configured to supply the first gas to the inside of the chamber, which opens near the outer periphery of the reflective surface to the reflective surface. A first gas supply unit through which the first gas flows and a second gas supplied to the inside of the chamber, between the first surface and the second focal point and within the obscure region. It comprises a second gas supply that is open at the position of, and an exhaust device that is configured to exhaust the gas inside the chamber and is open at a position between the first focal point and at least one magnet.

A method of controlling an extreme ultraviolet light generator according to one aspect of the present disclosure comprises a chamber and a reflective surface located inside the chamber that defines a first focus and a second focus. With an EUV condensing mirror configured so that the reflective surface and the second focal point are located across the first surface passing through the first focal point perpendicular to the first straight line passing through the second focal point and the second focal point. A control method for an extreme ultraviolet light generator comprising:, a first focal point and a magnetic field around the first focal point, and inside the chamber, from the vicinity of the outer peripheral portion of the reflecting surface to the reflecting surface. Supplying the first gas and supplying the inside of the chamber from a position between the first surface and the second focal point within the obscuring region, and supplying the second gas to the inside of the chamber. It includes exhausting the internal gas from the position where the magnetic field passes.

Some embodiments of the present disclosure will be described below, by way of example only, with reference to the accompanying drawings.
FIG. 1 schematically shows the configuration of an exemplary LPP EUV light generation system. FIG. 2A schematically shows the configuration of the EUV light generator according to the comparative example. FIG. 2B is a cross-sectional view taken along the line IIB-IIB of FIG. 2A. FIG. 2C is a cross-sectional view taken along the line IIC-IIC of FIG. 2A. FIG. 2D is a cross-sectional view taken along the IID-IID line of FIG. 2A. FIG. 3A schematically shows the configuration of the EUV light generator according to the first embodiment of the present disclosure. FIG. 3B is a cross-sectional view taken along the line IIIB-IIIB of FIG. 3A. FIG. 4A schematically shows the configuration of the EUV light generator according to the first modification. FIG. 4B is a cross-sectional view taken along the line IVB-IVB of FIG. 4A. FIG. 5A schematically shows the configuration of the EUV light generator according to the second modification. FIG. 5B is a cross-sectional view taken along the line VB-VB of FIG. 5A. FIG. 6A schematically shows the configuration of the EUV light generator according to the third modification. FIG. 6B is a cross-sectional view taken along the line VIB-VIB of FIG. 6A. FIG. 7A schematically shows the configuration of the EUV light generator according to the fourth modification. FIG. 7B is a cross-sectional view taken along the line VIIB-VIIB of FIG. 7A. FIG. 8A schematically shows the configuration of the EUV light generator according to the fifth modification. FIG. 8B is a cross-sectional view taken along the line VIIIB-VIIIB of FIG. 8A. FIG. 9A schematically shows the configuration of the EUV light generator according to the sixth modification. 9B is a cross-sectional view taken along the line IXB-IXB of FIG. 9A. FIG. 10A schematically shows the configuration of the EUV light generator according to the seventh modification. FIG. 10B is a cross-sectional view taken along the line XB-XB of FIG. 10A. FIG. 11A schematically shows the configuration of the EUV light generator according to the eighth modification. 11B is a cross-sectional view taken along the line XIB-XIB of FIG. 11A.

Embodiment

<Contents>
1. 1. Overall description of the extreme ultraviolet light generation system 1.1 Configuration 1.2 Operation 2. EUV light generator according to a comparative example 2.1 Chamber 2.2 EUV condensing mirror 2.3 Magnet 2.4 Exhaust device 2.5 First gas supply unit 2.6 Obscuring area 2.7 First Gas flow 2.8 Issue 3. EUV light generator equipped with a second gas supply unit 3.1 Configuration 3.2 Operation and operation 4. Variation of the second gas supply unit 4.1 First modification example 4.2 Second modification example 4.3 Third modification example 4.4 Fourth modification example 4.5 Fifth modification example 4. 6 Sixth modification example 4.7 Seventh modification example 4.8 Eighth modification example 5. others

Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. The embodiments described below show some examples of the present disclosure and are not intended to limit the content of the present disclosure. Moreover, not all of the configurations and operations described in each embodiment are essential as the configurations and operations of the present disclosure. The same components are designated by the same reference numerals, and duplicate description will be omitted.

1. 1. Overall Description of Extreme Ultraviolet Light Generation System 1.1 Configuration Figure 1 schematically shows the configuration of an exemplary LPP EUV light generation system. The EUV light generator 1 is used with at least one laser device 3. In the present application, the system including the EUV light generation device 1 and the laser device 3 is referred to as an EUV light generation system 11. As shown in FIG. 1 and described in detail below, the EUV light generator 1 includes a chamber 2 and a target supply unit 26. The chamber 2 is configured to be hermetically sealed. The target supply unit 26 is attached so as to penetrate the wall of the chamber 2, for example. The material of the target substance output from the target supply unit 26 contains tin. The material of the target material can also include a combination of tin with terbium, gadolinium, lithium, or xenon.

The wall of chamber 2 is provided with at least one through hole. A window 21 is provided in the through hole. The pulsed laser beam 32 output from the laser device 3 passes through the window 21. Inside the chamber 2, for example, an EUV condensing mirror 23 having a spheroidal reflecting surface is arranged. The EUV condensing mirror 23 has first and second focal points. On the surface of the EUV condensing mirror 23, for example, a multilayer reflective film in which molybdenum and silicon are alternately laminated is formed. The EUV focusing mirror 23 is arranged so that, for example, its first focus is located in the plasma generation region 25 and its second focus is located at the intermediate focusing point (IF) 292. A through hole 24 is provided in the central portion of the EUV condensing mirror 23. The pulsed laser beam 33 passes through the through hole 24.

The EUV light generation device 1 includes an EUV light generation control unit 5, a target sensor 4, and the like. The target sensor 4 has an imaging function and is configured to detect the presence, locus, position, speed, and the like of the target 27.

Further, the EUV light generation device 1 includes a connection portion 29 that communicates the inside of the chamber 2 with the inside of the exposure device 6. Inside the connection portion 29, a wall 291 on which an aperture is formed is provided. The wall 291 is arranged so that its aperture is located at the second focal position of the EUV condensing mirror 23.

Further, the EUV light generation device 1 includes a laser light traveling direction control unit 34, a laser light condensing mirror 22, a target recovery unit 28 for collecting the target 27, and the like. The laser beam traveling direction control unit 34 includes an optical element for defining the traveling direction of the laser beam and an actuator for adjusting the position, posture, and the like of the optical element.

1.2 Operation With reference to FIG. 1, the pulsed laser light 31 output from the laser device 3 passes through the window 21 as the pulsed laser light 32 via the laser light traveling direction control unit 34 and is incident on the chamber 2. .. The pulsed laser light 32 travels in the chamber 2 along at least one laser light path, is reflected by the laser light condensing mirror 22, and is irradiated to at least one target 27 as the pulsed laser light 33.

The target supply unit 26 outputs the target 27 toward the plasma generation region 25 inside the chamber 2. The target 27 is irradiated with at least one pulse contained in the pulse laser beam 33. The target 27 irradiated with the pulsed laser light is turned into plasma, and synchrotron radiation 251 is emitted from the plasma. The EUV condensing mirror 23 reflects the EUV light contained in the synchrotron radiation 251 with a higher reflectance than the light in another wavelength range. The reflected light 252 including the EUV light reflected by the EUV condensing mirror 23 is condensed at the intermediate condensing point 292 and output to the exposure apparatus 6. It should be noted that one target 27 may be irradiated with a plurality of pulses included in the pulsed laser beam 33.

The EUV light generation control unit 5 controls the control of the entire EUV light generation system 11. The EUV light generation control unit 5 processes the image data of the target 27 and the like captured by the target sensor 4. Further, the EUV light generation control unit 5 controls, for example, the timing at which the target 27 is output, the output direction of the target 27, and the like. Further, the EUV light generation control unit 5 controls, for example, the oscillation timing of the laser device 3, the traveling direction of the pulsed laser light 32, the condensing position of the pulsed laser light 33, and the like. The various controls described above are merely examples, and other controls may be added as needed.

2. 2. EUV light generator according to a comparative example FIG. 2A schematically shows the configuration of an EUV light generator according to a comparative example. FIG. 2B is a cross-sectional view taken along the line IIB-IIB of FIG. 2A. FIG. 2C is a cross-sectional view taken along the line IIC-IIC of FIG. 2A. FIG. 2D is a cross-sectional view taken along the IID-IID line of FIG. 2A.

2.1 Chamber As shown in FIGS. 2A and 2B, the chamber 2a has a substantially conical shape. The large-diameter end of the chamber 2a is sealed and fixed to the reference member 2b. An aperture 291a is formed at the end of the chamber 2a on the small diameter side.

2.2 EUV Condensing Mirror Inside the chamber 2a, the EUV condensing mirror 23 is supported by the reference member 2b by the EUV condensing mirror holder 23a. The EUV condensing mirror 23 has a spheroidal reflective surface, and a multilayer reflective film 231 is formed on the reflective surface. The multilayer reflective film 231 defines a first focal point and a second focal point. As mentioned above, the first focal point is located in the plasma generation region 25 and the second focal point is located at the intermediate focusing point 292. The straight line passing through the plasma generation region 25 and the intermediate condensing point 292 is referred to as a first straight line L1. The surface perpendicular to the first straight line L1 and passing through the plasma generation region 25 is referred to as the first surface P1. The multilayer reflective film 231 and the intermediate light collecting point 292 are located so as to sandwich the first surface P1. The central axis of the EUV light output direction from the multilayer reflective film 231 to the intermediate condensing point 292 substantially coincides with the first straight line L1 and the + Z direction. The output direction of the target 27 output from the target supply unit 26 substantially coincides with the + Y direction.

A cylindrical laser optical path wall 35 is arranged in the through hole 24 of the EUV condensing mirror 23 and the through hole of the reference member 2b. The pulsed laser beam 33 reflected by the laser beam focusing mirror 22 described with reference to FIG. 1 passes through the inside of the laser optical path wall 35. The pulsed laser beam 33 irradiates the target 27 supplied to the plasma generation region 25. When the target 27 is irradiated with the pulsed laser light 33, the target substance is turned into plasma, and the synchrotron radiation 251 is emitted from the plasma. After the synchrotron radiation 251 is emitted, the ions of the target substance contained in the plasma diffuse inside the chamber 2a as debris. The ions of the target substance may be neutralized and adhere to the surface of the multilayer reflective film 231.

A small amount of gas supplied from an external device (not shown) flows inside the chamber 2a through the inside of the laser optical path wall 35. Due to the flow of this small amount of gas, debris of the target substance is suppressed from flowing back inside the laser optical path wall 35, and the laser light condensing mirror 22 and the like are suppressed from being contaminated.

2.3 Magnets As shown in FIGS. 2A and 2C, magnets 7a and 7b are arranged outside the chamber 2a. Each of the magnets 7a and 7b is composed of an electromagnet having a superconducting coil. The magnets 7a and 7b are located so as to sandwich the plasma generation region 25. Further, the magnets 7a and 7b are arranged so that the central axes of the respective superconducting coils are substantially coaxial with each other and these central axes pass through the plasma generation region 25. By passing currents in the same directions through these superconducting coils, a magnetic field 70 is generated in and around the central axis of the superconducting coils. The central axis of the magnetic field 70 substantially coincides with the central axis of the superconducting coil and the + X direction.
The magnetic flux density in the plasma generation region 25 is preferably 0.4 T or more and 3.0 T or less. More preferably, it may be 0.5T or more and 1.5T or less.

Some of the ions of the target substance that are about to diffuse inside the chamber 2a are trapped by the magnetic field 70. Therefore, it is considered that a large amount of the target substance is distributed around the broken line shown as the magnetic field 70 in FIGS. 2A and 2C.

2.4 Exhaust device An exhaust device is attached to the chamber 2a. The exhaust device includes an exhaust pump 30a and an exhaust pipe 30b. One end of the exhaust pipe 30b is connected to the exhaust pump 30a, and the other end is connected to the inside of the chamber 2a at the opening 30c. The openings 30c are arranged between the plasma generation region 25 and the magnet 7a, and between the plasma generation region 25 and the magnet 7b, respectively. Alternatively, the openings 30c are arranged in the vicinity of the magnet 7a and the vicinity of the magnet 7b, respectively, or at positions where the magnetic field 70 passes. Exhaust devices also include fine particle traps and abatement devices (not shown).

The exhaust pump 30a exhausts the inside of the chamber 2a so as to have a predetermined pressure lower than the atmospheric pressure. Since the opening 30c is located near the magnetic field 70 in which a large amount of the target substance is distributed, the exhaust device can efficiently discharge the target substance inside the chamber 2a.

2.5 First gas supply unit A first gas supply unit is attached to the chamber 2a. The first gas supply unit includes an etching gas supply source 10a and a gas supply pipe 10b. The etching gas supply source 10a includes a gas cylinder (not shown) and a pressure control device or a flow rate control device. The gas supply pipe 10b penetrates the reference member 2b. One end of the gas supply pipe 10b is connected to the etching gas supply source 10a outside the chamber 2a, and the other end is located inside the chamber 2a. The gas supply pipe 10b has a plurality of first openings 10c in the vicinity of the outer peripheral portion of the reflective surface of the EUV condensing mirror 23. The plurality of first openings 10c are arranged along the outer peripheral portion of the reflective surface.

As shown by arrows F1 in FIGS. 2A to 2C, the first gas supply unit is configured to allow the first gas supplied from the etching gas supply source 10a to flow along the surface of the multilayer reflective film 231. Has been done. The first gas flows from the outer peripheral portion of the reflecting surface in a direction approaching the first straight line L1.

The first gas contains an etching gas. The etching gas includes hydrogen gas. Part of the hydrogen gas is excited by EUV light to become hydrogen radicals. When tin is used as the target substance, hydrogen radicals react with tin to produce stannane, which is a gas at room temperature. As a result, tin adhering to the surface of the multilayer reflective film 231 is etched. Alternatively, the adhesion of tin to the surface of the multilayer reflective film 231 is suppressed. The stannan gas is exhausted to the outside of the chamber 2a by the exhaust device through the opening 30c.

Since stannane tends to separate into hydrogen and tin at high temperatures, the EUV condensing mirror 23 is cooled to a predetermined temperature or lower by a cooling device (not shown). The predetermined temperature is preferably room temperature or lower. More preferably, it may be, for example, 5 ° C.

2.6 Obscuring Region FIG. 2D shows a cross section of the optical path of the reflected light 252 from the EUV focusing mirror 23 to the intermediate focusing point 292. When the EUV condensing mirror 23 is viewed along the first straight line L1, the EUV condensing mirror 23 has a substantially circular outer shape. Therefore, the cross section of the optical path of the reflected light 252 including EUV light also has a substantially circular outer shape.

However, even if the cross section of the EUV light path has such a circular outer shape, a region not used for exposure may be set according to the specifications of the exposure apparatus 6 described with reference to FIG. The spatial region inside the chamber 2a corresponding to such a region is referred to as an obscure region. FIG. 2D shows a cross section of the obscure region with reference numeral OA. Since EUV light may be shielded in the obscure region, it is possible to install a member that does not transmit EUV light in the obscure region. The obscure area will be described later.

2.7 First gas flow As shown by the arrow F1 in FIGS. 2A to 2C, the first gas flows from the outer peripheral portion of the reflective surface of the EUV condensing mirror 23 to the vicinity of the center of the EUV condensing mirror 23. get together. Since there is no escape place for the gas in the −Z direction near the center of the EUV condensing mirror 23, the first gas turns in the + Z direction as shown in FIGS. 2A and 2B. Since the first gas flow from the vicinity of the center of the EUV condensing mirror 23 in the + Z direction is composed of the gas collected from the outer peripheral portion of the reflective surface, it may be a strong flow. This strong flow entrains a large amount of target material distributed around the plasma generation region 25 and travels in the + Z direction along the first straight line L1 as indicated by the arrow F2.

The first gas entrained with the target substance is then turned back in front of the aperture 291a and turned in the −Z direction. Since there is a strong flow in the + Z direction near the first straight line L1, the first gas cannot flow in the −Z direction near the first straight line L1. There, the first gas flows in the −Z direction along the wall surface of the chamber 2a at a position away from the first straight line L1 as indicated by arrows F3 and F4.

From the exposure apparatus 6, a small amount of gas flows into the chamber 2a through the aperture 291a. Due to this small amount of gas flow, debris of the target substance is suppressed from contaminating the optical element inside the exposure apparatus 6. That is, the first gas does not flow out of the chamber 2a through the aperture 291a.

2.8 Problem A part of the first gas folded back before the aperture 291a reaches the vicinity of the opening 30c and is exhausted by the exhaust device as shown by the arrow F3. However, another portion of the first gas folded back before aperture 291a may reach the periphery of the multilayer reflective film 231 as indicated by arrow F4. The first gas that reaches the periphery of the multilayer reflective film 231 contains a large amount of a target substance, and this target substance may contaminate the multilayer reflective film 231.

In the embodiment described below, by supplying the second gas from between the first surface P1 and the intermediate condensing point 292, the target substance contained in the first gas contaminates the multilayer reflective film 231. Suppress doing.

3. 3. EUV light generator 3.1 configuration including a second gas supply unit FIG. 3A schematically shows the configuration of the EUV light generator according to the first embodiment of the present disclosure. FIG. 3B is a cross-sectional view taken along the line IIIB-IIIB of FIG. 3A. FIG. 3A shows a portion corresponding to FIG. 2A in the above-mentioned comparative example, and FIG. 3B shows a portion corresponding to FIG. 2B. As shown in FIGS. 3A and 3B, the EUV light generator according to the first embodiment is different from the EUV light generator according to the comparative example in that it includes a second gas supply unit. Other points are the same as in the comparative example.

The second gas supply unit includes an etching gas supply source 20a and a gas supply pipe 20b. The etching gas supply source 20a includes a gas cylinder (not shown) and a pressure control device or a flow rate control device. The etching gas supply source 20a may be prepared separately from the etching gas supply source 10a, or may use a gas cylinder common to the etching gas supply source 10a.

One end of the gas supply pipe 20b is connected to the etching gas supply source 20a outside the chamber 2a, and the other end is connected to the gas supply pipe 203 inside the chamber 2a. A part of the gas supply pipe 20b may be common with a part of the gas supply pipe 10b. The gas supply pipe 20b and the gas supply pipe 203 may be composed of one pipe penetrating the wall of the chamber 2a. The gas supply pipe 203 has a second opening 20c. The second opening 20c is located between the first surface P1 and the intermediate condensing point 292.

As indicated by the arrow F5, the second gas supply unit is configured to supply the second gas supplied from the etching gas supply source 20a to the inside of the chamber 2a. The second gas contains an etching gas. The etching gas includes hydrogen gas. The first gas that has passed through the plasma generation region 25 or its vicinity contains a large amount of the target substance, whereas the second gas contains almost no target substance.

The amount of the second gas supplied to the inside of the chamber 2a is preferably 0.6 times or more and 4 times or less the amount of the first gas supplied to the inside of the chamber 2a. The amount of the second gas supplied to the inside of the chamber 2a is preferably larger than the amount of the first gas supplied to the inside of the chamber 2a.
The amount of the second gas supplied to the inside of the chamber 2a is preferably 20 slm or more and 200 slm or less. For example, it may be 60 slm.
The amount of the first gas supplied to the inside of the chamber 2a is preferably 10 slm or more and 120 slm or less. For example, it may be 40 slm.
In addition, "Xslm" means that it is X liters per minute when converted into 1 atm.

The temperature of the first gas and the second gas supplied to the inside of the chamber 2a is preferably 16 ° C. or lower.
The exhaust device is controlled so that the pressure inside the chamber 2a is 50 Pa or more and 150 Pa or less. Preferably, the pressure inside the chamber 2a may be 60 Pa or more and 90 Pa or less. For example, the pressure inside the chamber 2a may be 75 Pa.

3.2 Operation and action The second gas supplied inside the chamber 2a is directed in the −Z direction to push the first gas towards the opening 30c of the exhaust system, as indicated by arrow F6. It flows.

In the vicinity of the first straight line L1, as shown by the arrow F2, the first gas strongly flows in the + Z direction. Further, outside the arrow F2, as indicated by the arrows F3 and F4, the first gas folded back in the −Z direction flows.

Therefore, a part of the second gas flows in the −Z direction along the wall surface of the chamber 2a at a position further outside the arrows F3 and F4, as shown by the arrow F7 in FIG. 3B. In other words, the second gas flow indicated by the arrows F7 attempts to push the first gas flow indicated by the arrows F3 and F4 away from the wall surface of the chamber 2a and toward the first straight line L1. do. Further, since the second gas flow indicated by the arrow F7 reaches the periphery of the multilayer reflective film 231 along the wall surface of the chamber 2a, the first gas flow indicated by the arrow F4 reaches the periphery of the multilayer reflective film 231. Reaching the surrounding area is suppressed. In this way, most of the first gas does not reach the wall surface of the chamber 2a and the periphery of the multilayer reflective film 231 but is pushed by the second gas and exhausted by the exhaust device. Therefore, it is possible to prevent the wall surface of the chamber 2a and the multilayer reflective film 231 from being contaminated with the target substance.

Another portion of the second gas flows in the −Z direction along the wall surface of chamber 2a at a position further outside the arrows F3 and F4, as shown by arrow F8 in FIG. 3A. Therefore, it is possible to prevent the wall surface of the chamber 2a from being contaminated with the target substance. If the flow of the second gas indicated by the arrow F8 crosses the magnetic field 70 and reaches the multilayer reflective film 231, the second gas causes the target substance, which is largely distributed in the magnetic field 70, to reach the multilayer reflective film 231. There is a possibility that it will end up. However, in the present embodiment, since the opening 30c of the exhaust device is arranged in the vicinity of the magnetic field 70 in which a large amount of the target substance is distributed, most of the second gas indicated by the arrow F8 does not reach the multilayer reflective film 231. Is exhausted from the opening 30c. Therefore, it is possible to prevent the multilayer reflective film 231 from being contaminated with the target substance.

4. Variation of Second Gas Supply Unit 4.1 First Modification Example FIG. 4A schematically shows the configuration of the EUV light generator according to the first modification. FIG. 4A shows a portion corresponding to FIG. 3A or FIG. 3B in the first embodiment described above. FIG. 4B is a cross-sectional view taken along the line IVB-IVB of FIG. 4A. In FIGS. 4A and 4B, the etching gas supply source 10a, the gas supply pipe 10b, the exhaust pump 30a, the exhaust pipe 30b, the magnets 7a and 7b, the target supply unit 26, the target recovery unit 28, and the arrow F2 indicating the gas flow. Illustrations of F3, F4, F6, F7, F8, etc. are omitted. These are the same as those described with reference to FIGS. 3A and 3B.

In the EUV light generator according to the first modification, only one second opening 20d is formed in the gas supply pipe 204 connected to the gas supply pipe 20b. The second gas supply unit discharges the second gas toward the first straight line L1 in a direction substantially parallel to the first surface P1. Also in this configuration, a second gas flow in the −Z direction is formed along the wall surface of the chamber 2a.
Other points are the same as those described with reference to FIGS. 3A and 3B.

4.2 Second Modification Example FIG. 5A schematically shows the configuration of the EUV light generator according to the second modification. FIG. 5A shows a portion corresponding to FIG. 3A or FIG. 3B in the first embodiment described above. FIG. 5B is a cross-sectional view taken along the line VB-VB of FIG. 5A. In FIGS. 5A and 5B, the etching gas supply source 10a, the gas supply pipe 10b, the exhaust pump 30a, the exhaust pipe 30b, the magnets 7a and 7b, the target supply unit 26, the target recovery unit 28, and the arrow F2 indicating the gas flow. Illustrations of F3, F4, F6, F7, F8, etc. are omitted. These are the same as those described with reference to FIGS. 3A and 3B.

In the EUV light generator according to the second modification, only one second opening 20e is formed in the gas supply pipe 205 connected to the gas supply pipe 20b. The second gas supply unit discharges the second gas toward the first straight line L1 in a direction inclined away from the first surface P1. Also in this configuration, the second gas folds back in the −Z direction in front of the aperture 291a, so that a flow of the second gas in the −Z direction along the wall surface of the chamber 2a is formed. By folding back the second gas in front of the aperture 291a, it is possible to suppress the bias of the flow of the second gas in the −Z direction along the wall surface of the chamber 2a and make the flow uniform.
Other points are the same as those described with reference to FIGS. 3A and 3B.

4.3 Third Modification Example FIG. 6A schematically shows the configuration of the EUV light generator according to the third modification. FIG. 6A shows a portion corresponding to FIG. 3A or FIG. 3B in the first embodiment described above. FIG. 6B is a cross-sectional view taken along the line VIB-VIB of FIG. 6A. In FIGS. 6A and 6B, the etching gas supply source 10a, the gas supply pipe 10b, the exhaust pump 30a, the exhaust pipe 30b, the magnets 7a and 7b, the target supply unit 26, the target recovery unit 28, and the arrow F2 indicating the gas flow. Illustrations of F3, F4, F6, F7, F8, etc. are omitted. These are the same as those described with reference to FIGS. 3A and 3B.

In the EUV light generator according to the third modification, the annular gas supply pipe 201 is connected to the gas supply pipe 20b. The gas supply pipe 201 is arranged outside the chamber 2a so as to surround the chamber 2a. A plurality of gas supply pipes 206 are connected to the gas supply pipe 201. Each of the plurality of gas supply pipes 206 penetrates the wall of the chamber 2a and has an opening 20f located inside the chamber 2a. The second gas supply unit discharges the second gas from a plurality of positions surrounding the first straight line L1 toward the first straight line L1. Also in this configuration, a second gas flow in the −Z direction is formed along the wall surface of the chamber 2a. By discharging the second gas from a plurality of positions surrounding the first straight line L1, the flow of the second gas along the wall surface of the chamber 2a is suppressed from being biased in the −Z direction, resulting in a uniform flow. can do.
Other points are the same as those described with reference to FIGS. 3A and 3B.

4.4 Fourth modified example FIG. 7A schematically shows the configuration of the EUV light generator according to the fourth modified example. FIG. 7A shows a portion corresponding to FIG. 3A or FIG. 3B in the first embodiment described above. FIG. 7B is a cross-sectional view taken along the line VIIB-VIIB of FIG. 7A. In FIGS. 7A and 7B, the etching gas supply source 10a, the gas supply pipe 10b, the exhaust pump 30a, the exhaust pipe 30b, the magnets 7a and 7b, the target supply unit 26, the target recovery unit 28, and the arrow F2 indicating the gas flow. Illustrations of F3, F4, F6, F7, F8, etc. are omitted. These are the same as those described with reference to FIGS. 3A and 3B.

In the EUV light generator according to the fourth modification, an annular gas supply pipe 207 is connected to the gas supply pipe 20b. The gas supply pipe 207 is arranged so as to surround the first straight line L1. The gas supply pipe 207 has a slit-shaped opening 20 g. The opening 20 g may have an opening width of, for example, 7.5 mm. The second gas supply unit discharges the second gas from the periphery of the first straight line L1 toward the first straight line L1. Also in this configuration, a second gas flow in the −Z direction is formed along the wall surface of the chamber 2a. By discharging the second gas from the periphery of the first straight line L1, it is possible to suppress the bias of the flow of the second gas in the −Z direction along the wall surface of the chamber 2a and make the flow uniform. can.
Other points are the same as those described with reference to FIGS. 3A and 3B.
The shape of the opening 20 g may be a mesh shape as well as a slit shape.

4.5 Fifth Modification Example FIG. 8A schematically shows the configuration of the EUV light generator according to the fifth modification. FIG. 8A shows a portion corresponding to FIG. 3A or FIG. 3B in the first embodiment described above. FIG. 8B is a cross-sectional view taken along the line VIIIB-VIIIB of FIG. 8A. In FIGS. 8A and 8B, the etching gas supply source 10a, the gas supply pipe 10b, the exhaust pump 30a, the exhaust pipe 30b, the magnets 7a and 7b, the target supply unit 26, the target recovery unit 28, and the arrow F2 indicating the gas flow. Illustrations of F3, F4, F6, F7, F8, etc. are omitted. These are the same as those described with reference to FIGS. 3A and 3B.

In the EUV light generator according to the fifth modification, a plurality of gas supply pipes 208 are connected to the gas supply pipe 20b. Each of the plurality of gas supply pipes 208 penetrates the wall of the chamber 2a and has an opening 20h located inside the chamber 2a. The second gas supply unit discharges the second gas in the −Z direction along the wall surface of the chamber 2a from a plurality of positions surrounding the first straight line L1. Also in this configuration, a second gas flow in the −Z direction is formed along the wall surface of the chamber 2a. By discharging the second gas at a plurality of positions surrounding the first straight line L1, the flow of the second gas along the wall surface of the chamber 2a is suppressed from being biased in the −Z direction, resulting in a uniform flow. can do.
Other points are the same as those described with reference to FIGS. 3A and 3B.

4.6 Sixth Modification Example FIG. 9A schematically shows the configuration of the EUV light generator according to the sixth modification. FIG. 9A shows a portion corresponding to FIG. 3A or FIG. 3B in the first embodiment described above. 9B is a cross-sectional view taken along the line IXB-IXB of FIG. 9A. In FIGS. 9A and 9B, the etching gas supply source 10a, the gas supply pipe 10b, the exhaust pump 30a, the exhaust pipe 30b, the magnets 7a and 7b, the target supply unit 26, the target recovery unit 28, and the arrow F2 indicating the gas flow. Illustrations of F3, F4, F6, F7, F8, etc. are omitted. These are the same as those described with reference to FIGS. 3A and 3B.

In the EUV light generator according to the sixth modification, the gas supply pipe 209 connected to the gas supply pipe 20b is arranged in the obscure region described with reference to FIG. 2D. A plurality of second openings 20i are formed in the gas supply pipe 209. Instead of the plurality of second openings 20i, slit-shaped or mesh-shaped openings may be formed. The second gas supply unit discharges the second gas toward the wall of the chamber 2a in a direction substantially parallel to the first surface P1. Also in this configuration, a second gas flow in the −Z direction is formed along the wall surface of the chamber 2a. By arranging the gas supply tube 209 in the obscure region, the second gas can be supplied without affecting the exposure performance of the exposure apparatus 6.
Other points are the same as those described with reference to FIGS. 3A and 3B.

4.7 Seventh variant

FIG. 10A schematically shows the configuration of the EUV light generator according to the seventh modification. FIG. 10A shows a portion corresponding to FIG. 3A or FIG. 3B in the first embodiment described above. FIG. 10B is a cross-sectional view taken along the line XB-XB of FIG. 10A. In FIGS. 10A and 10B, the etching gas supply source 10a, the gas supply pipe 10b, the exhaust pump 30a, the exhaust pipe 30b, the magnets 7a and 7b, the target supply unit 26, the target recovery unit 28, and the arrow F2 indicating the gas flow. Illustrations of F3, F4, F6, F7, F8, etc. are omitted. These are the same as those described with reference to FIGS. 3A and 3B.

In the EUV light generator according to the seventh modification, the gas supply pipe 210 connected to the gas supply pipe 20b is arranged in the obscure region described with reference to FIG. 2D. A plurality of second openings 20j are formed in the gas supply pipe 210. The second gas supply unit discharges the second gas in a direction away from the first surface P1. Also in this configuration, the second gas folds back in the −Z direction in front of the aperture 291a, so that a flow of the second gas in the −Z direction along the wall surface of the chamber 2a is formed. By folding back the second gas in front of the aperture 291a, it is possible to suppress the bias of the flow of the second gas in the −Z direction along the wall surface of the chamber 2a and make the flow uniform.
Other points are the same as those of the sixth modification.

4.8 Eighth Modification Example FIG. 11A schematically shows the configuration of the EUV light generator according to the eighth modification. FIG. 11A shows a portion corresponding to FIG. 3A or FIG. 3B in the first embodiment described above. 11B is a cross-sectional view taken along the line XIB-XIB of FIG. 11A. In FIGS. 11A and 11B, the etching gas supply source 10a, the gas supply pipe 10b, the exhaust pump 30a, the exhaust pipe 30b, the magnets 7a and 7b, the target supply unit 26, the target recovery unit 28, and the arrow F2 indicating the gas flow. Illustrations of F3, F4, F6, F7, F8, etc. are omitted. These are the same as those described with reference to FIGS. 3A and 3B.

In the EUV light generator according to the eighth modification, the gas supply pipe 211 connected to the gas supply pipe 20b is arranged in the obscure region described with reference to FIG. 2D. The gas supply pipe 211 is formed with only one second opening 20k at a position where the first straight line L1 passes. The second gas supply unit discharges the second gas in a direction away from the first surface P1. Also in this configuration, the second gas folds back in the −Z direction in front of the aperture 291a, so that a flow of the second gas in the −Z direction along the wall surface of the chamber 2a is formed. Since the second opening 20k is formed at the position where the first straight line L1 passes, the flow of the second gas in the −Z direction along the wall surface of the chamber 2a is suppressed from being biased, and a uniform flow is suppressed. Can be.
Other points are the same as those of the sixth modification.

5. Others The above description is intended to be merely an example, not a limitation. Accordingly, it will be apparent to those skilled in the art that modifications can be made to the embodiments of the present disclosure without departing from the appended claims.

The terms used throughout this specification and the appended claims should be construed as "non-limiting" terms. For example, the term "contains" or "contains" should be construed as "not limited to what is described as being included." The term "have" should be construed as "not limited to what is described as having." Also, the modifier "one" described herein and in the appended claims should be construed to mean "at least one" or "one or more."

Claims (16)

With the chamber
Located inside the chamber, it has a reflective surface that defines a first focal point and a second focal point, and the first focal point is perpendicular to a first straight line passing through the first focal point and the second focal point. An EUV condensing mirror configured so that the reflective surface and the second focal point are located so as to sandwich the first surface passing through the focal point of the above.
At least one magnet that generates a magnetic field around the first focal point and the first focal point,
A first gas supply unit configured to supply the first gas to the inside of the chamber, opening in the vicinity of the outer peripheral portion of the reflection surface, and flowing the first gas to the reflection surface.
A second gas supply unit configured to supply a second gas to the inside of the chamber and opened at a position within the obscure region between the first surface and the second focal point. When,
An exhaust device configured to exhaust gas inside the chamber and opened at a position between the first focal point and the at least one magnet.
Extreme ultraviolet light generator equipped with. The extreme ultraviolet light generator according to claim 1.
The at least one magnet includes a first magnet and a second magnet arranged across the first focal point.
The exhaust device is open in the vicinity of the first magnet and in the vicinity of the second magnet, respectively.
Extreme ultraviolet light generator. The extreme ultraviolet light generator according to claim 1.
The first gas supply unit is configured to flow the first gas in a direction approaching the first straight line.
Extreme ultraviolet light generator. The extreme ultraviolet light generator according to claim 1.
The first gas supply unit has a plurality of first openings arranged along the outer peripheral portion of the EUV condensing mirror.
Extreme ultraviolet light generator. The extreme ultraviolet light generator according to claim 1.
The second gas supply unit causes the second gas to flow in a direction away from the first surface.
Extreme ultraviolet light generator. The extreme ultraviolet light generator according to claim 1.
The flow rate of the second gas supplied by the second gas supply unit is 0.6 times or more and 4 times or less the flow rate of the first gas supplied by the first gas supply unit.
Extreme ultraviolet light generator. The extreme ultraviolet light generator according to claim 1.
The flow rate of the second gas supplied by the second gas supply unit is larger than the flow rate of the first gas supplied by the first gas supply unit.
Extreme ultraviolet light generator. The extreme ultraviolet light generator according to claim 1.
The flow rate of the first gas supplied by the first gas supply unit is 120 liters or less per minute when converted to 1 atm.
Extreme ultraviolet light generator. The extreme ultraviolet light generator according to claim 1.
The flow rate of the second gas supplied by the second gas supply unit is 200 liters or less per minute when converted to 1 atm.
Extreme ultraviolet light generator. The extreme ultraviolet light generator according to claim 1.
The first gas contains an etching gas.
Extreme ultraviolet light generator. The extreme ultraviolet light generator according to claim 1.
The second gas contains an etching gas.
Extreme ultraviolet light generator. The extreme ultraviolet light generator according to claim 1.
The first gas contains hydrogen gas.
Extreme ultraviolet light generator. The extreme ultraviolet light generator according to claim 1.
The second gas contains hydrogen gas.
Extreme ultraviolet light generator. The extreme ultraviolet light generator according to claim 1.
The temperature of the second gas is 16 ° C. or lower.
Extreme ultraviolet light generator. The extreme ultraviolet light generator according to claim 1.
The exhaust device exhausts the gas inside the chamber so that the pressure inside the chamber is 50 Pa or more and 150 Pa or less.
Extreme ultraviolet light generator. With the chamber
Located inside the chamber, it has a reflective surface that defines a first focal point and a second focal point, and the first focal point is perpendicular to a first straight line passing through the first focal point and the second focal point. An EUV condensing mirror configured so that the reflective surface and the second focal point are located so as to sandwich the first surface passing through the focal point of the above.
It is a control method of an extreme ultraviolet light generator equipped with
To generate a magnetic field around the first focal point and the first focal point,
To supply the first gas to the reflective surface from the vicinity of the outer peripheral portion of the reflective surface into the inside of the chamber.
To supply the inside of the chamber with a second gas from a position within the obscure region between the first surface and the second focal point.
Exhausting the gas inside the chamber from the position where the magnetic field passes,
How to control an extreme ultraviolet light generator, including.

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